Antioxidant or age-retarder



Patented Mar. 15, 1932 UNITED STATES- 1,s4e,saa

ALBERT M. CLIFFORD, or AKRON, e10, Assrenon TO THE GOODYEAR TIRE & Benign-a COMPANY, OF AKRON, OHIO, A. CORPORATION OF OHIO mroxrnnnr on AGE-RETARDER N0 Drawing. Original application filed. March 1, 1928, Serial No. 258,442. Divided and. this application filed March a, 1929.

My invention relates to methods of treating rubber and the product formed thereby and it has particular relationto a method of treatment whereby the durability of rub- 5 her maybe greatly enhanced.

This application is a division of application Serial No. 258,442, filed March 1,1928 which has resulted in Patent No. 1,763,579,

More specifically, the invention has for one of its objects the provision of a material which, when it is incorporated into rubber compounds, inhibits the absorption of oxygen and thus prevents premature loss of elasticity and tensile strength of the rubber.

Another object of the invention is to provide a non-odorous and non-poisonous antioxidant orageretarder which may readily be incorporated into rubber, V V

Another object of the invention is to provide an anti-oxidant or age-retarder which is highly efiicient in action and which is relativelyinexpensive to manufacture. 5

One difliculty heretofore experiencedwith rubber compounds has been due to the absorption of oxygen which results in premature loss of elasticity and tensile strength of the compound. It has been proposed to overcome this difficulty by incorporating into the rubber prior to vulcanlzation a compound which inhibits the absorption of the oxygen.

them are more or less unsatisfactory for Some of them exist normally only in a liquid state and for that reason can be incorporated into the rubber only with considerable difficulty. Some of these materials also possess strong and unpleasant odors which render the handling thereof an unpleasant task. Still others are more or less poisonous in their nature and their use in rubber compounds is likely to produce toxic effects upon the workmen employed in handling them.

This invention consists in the discovery that certain amino benzyl alcohols may be readily manufactured and incorporated into rubber compounds as antioxidants or ageretarders with highly gratifying results.

One material of this class is p-(alpha- 7 ing the formula A relatively large number of compounds have f been proposed for this purpose. but most of Serial No. 345,893.

new omen naphthyl amido) benzylalcohol which may Q be prepared by the following method.

Dissolve phenyl alpha-naphthylamine in alcohol inthe proportions of 16 grams of the amine to 275 cc. of alcohol. .Treatj this solution with 8.8 grams of hydrochloric acid having a specific gravity of 1.17. The re sulting solution should then be treated with 5.45 grams of a forty percent solution of formaldehyde. It may be necessary towarm this solution slightly before reaction takes place. The reaction results in a curdy precipitate which is allowed to stand until pren'aphthylamine for phenyl alpha-naphthylaminer 4 I v The inventionisnot limited to the naph thyla'mido benz'yl' alcohols, as antioxidants but includes also the phenyl amido ben z'yl alcohols, and other alcohols of the classhavin which 'R represents a hydrocarbon group. 85

,y The substances just discussed may beemployed in most of the standard rubber com-j pounds with satisfactory'results; The fol-- lowing is an example of a'formula which insures a compound having excellent physical Samples of material prepared in accordcharacteristics. a P M 1 arts Acetone extracted rubber 1100- Zinc oxide ;y 35 Sulfur- -2 3 Stearicacid 1.5'

Hexamethylene tetramine .1- Antioxidant 1" A ployed as antioxidants were subjected to vulcanization. Certain of the vulcanized samples were thensubjected to physical tests in order to ascertain their elasticity and tensile strength prior to aging. Other samples of the same material were subjected to artificial aging for a period of six days in an oxygen bomb containing oxygen under a pressure of 150pounds per square inch and ata temperature of C. The results of these tests are indicated in the following tables:

V Stress in kgs/cm. atp v cm elong. Per cent in $233 I 0 at weight mins. p 500 700 Break break Increase 1 elong. elong.

I IPHENYLAMID O) BENZYL ALCOHOL V ORIGINAL a0 40 15 44 105 865 50. '40 22 73 165 i 835 v 40 29 106 170 7.80

' I AGE 'rrsr 30 40 22 70 775 .05 a0 40 29 100 130 750 .35 70 40 3s 635 .52 P-(ALPHA-NAPHTHYLAMID 0)- BENZYL ALCOHOL i .7 ORIGINAL' 30 40 17' 52 -14o 885 so 4o 22 so 165 830 10 40 29 110 a 190 795 I AGE run so 1 4o 7 17 6'1 840 r 12 50 40 25 90 160 805 .11 70 1o 34 124 165 750 14 P-(BETA-NAPHTHYLAMIDO) BENZYL ALCOHOL V ORIGINAL V i 30 40 17 50 115 855 50 40 2a 83 i s15 70 7 40' 30 115 180 vso I AGE rrsr V g 7 30 40 1s 61 135 855 .14 so 40 26 I 90' 79o .17 70 4o 33 124 750 .23

novel and highly satisfactory method for increasing the durability of rubber compounds. The method does not involve the being composed solely of carbon and hydrogen and being directly attached to the nitrogen atom.

2. A rubber product that has been vulcanized in the presence of a reaction product of diphenylamine and formaldehyde.

3. A rubber, product that has been vulcanized in the presence of the reaction product of a diarylsubstituted amine andformaldehyde, said amine being composed solely of carbon, hydrogen and nitrogen and having its tached to the amine groupand consisting solely of carbon, hydrogen and nitrogen.

7 A rubber product that has been vulcanized in the presence of a reaction product of molar proportionsofformaldehyde and a secondary amine 7 containing two benzene groups directly attached to the nitrogen atom,

such amine being composed solely of carbon,

hydrogen and nitrogen.

In witness whereof, I have hereunto signed my name.

.Signed at Akron, in the county of Summit and State of Ohio, U. S. A., this 8th day of March, 1929.

. ALBERT M. CLIFFORD.

employment of any poisonous or 'malodorous materials. The compounds employed are also powder-like substances which may be readily and uniformly dispersed throughout arubber mass. I

-Although I have described in detail only the preferred forms which the invention may in which R isa benzene group, said group assume, it will be apparent to those skilled in the art that it is not so limited but that vari- .ous minor modifications may be made therein -without departing from the spirit of the invention or from the scope of the appended claims. 1 V 1 I "WhatIcIaimisr 1 1. A rubber product that has been vulcanizjed in the presence of a material having the formula H I I B-N-OdLCHzOH,

so f 

